Re: Power consumption HZ100, HZ250, HZ1000: new numbers

[Hans Kristian Rosbach <hans.kristian@isphuset.no>]

On Wed, 2005-08-03 at 08:57 -0500, Dmitry Torokhov wrote:
> On 8/3/05, Hans Kristian Rosbach <hans.kristian@isphuset.no> wrote:
> > On Tue, 2005-08-02 at 00:50 -0400, James Bruce wrote:
> > > Theodore Ts'o wrote:
> > >  > On Mon, Aug 01, 2005 at 12:18:18PM -0400, James Bruce wrote:
> > >  >>The tradeoff is a realistic 4.4% power savings vs a 300% increase in
> > >  >>the minimum sleep period.  A user will see zero power savings if they
> > >  >>have a USB mouse (probably 99% of desktops).  On top of that, we can
> > >                                      ^^^^^^^^
> > >
> > >  > Most laptops (including mine, a Thinkpad T40) use a PS/2 mouse.  So in
> > >  > the places where power consumption savins matters most, it's usually
> > >  > quite possible to function without needing any USB devices.  The 90%
> > >  > figure isn't at all right; in fact, it may be that over 90% of the
> > >  > laptops still use PS/2 mice and keyboards.
> > >
> > > Yes, laptops are mostly PS/2, which is why I only claimed a statistic
> > > for desktops.  Desktops pretty much all use USB mice now.  If 250Hz were
> > > only being sold as an option for laptops, we could leave it at that, yet
> > > its being pushed as a default that's "good for everyone".  For desktops
> > > this is not currently true at all.  By the time USB is fixed to do power
> > > saving, we'll probably have a working tick-skipping patch which makes
> > > the whole HZ argument moot.
> > 
> > Most new laptops are moving away from PS/2 ports, for example my
> > shining (literally) new Acer Ferrari 4005 only has USB2 ports for mice
> > and keyboard inputs (unless in the optional pcie docking station maybe).
> > So my suggestion would be to fix USB power management.
> >
> 
> You are talking about external ports. I am pretty sure that installed
> keyboard and touchpad (or whattever pointing device it has) are plain
> old PS/2.

Well, yes..

But as I _never_ use the touchpad, it is quite necessary to keep USB
enabled for me at any time as an external PS2 mouse is not possible.

-HK

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/